1. Field of the Invention
The invention relates to an antenna, and more particularly, to an antenna structure having a sheet-shaped capacitor.
2. Description of Prior Art
Currently, many portable electronic devices will adopt the exposed type antenna structure in order to have a good reception, but the exposed antenna structure not only fails to meet a design of miniaturized form device, but also fails to meet a need of built-in design of antenna.
In order to achieve a miniaturized design of antenna, manufacturers mainly provide a planar antenna pattern on a substrate, and layout the planar antenna pattern by adjusting the ratio of major axis and minor axis, as well as non-uniform line width in accordance with the operation feature of reception and emission of signals to achieve an antenna with nearly omnidirection radiation field. However, it is not easy to adjust the ratio of major axis and minor axis, as well as non-uniform line width of the planar antenna pattern provided on the antenna in the design, and planar antenna pattern will become more complex and difficult to layout, thus there is a problem in the design of miniaturized antennas.